M4000 M5100 W5170 M6000 support (AMD Radeon R9 M370X 2GB)

The GPU chip has a marketing name Venus and has been used on at least all these listed cards below. The M4000 offers 1GB VRAM, there is a single M5100 model used by HP with 4 GB VRAM, all other models offer 2 GB. The performance depends on clock speed and differs barely.

M6000 (eDP, only)

Type	ident	BIOS version	device-id	working
Blue AMD PCB	109-C42251-00B	M6000	6825	yes

Performance:

• GeekBench Metal and OpenCL: > 10.000
• Valley: 24 FPS, 1010 Score
• MetalBench: 30 MRays/s
• TPD 43W

Heat Sink mods:

• card needs small heat sink modification (sheet attached picture) on iMac11,x MXM-B sinks (used with HD 4850 and HD 5850)
• card needs copper plate (0.8 mm) or another heat sink mod on top (purple) to avoid bending of the card after fixing screws

This GPU will be identified by the macOS as AMD FirePro M6000 and by MetalBench and GeekBench5 as AMD Radeon R9 M370X. The current vBIOS supports Hynix video memory. The card is of type MXM-B and will not fit into well 21.5 inch models, although power draw is low.

M4000 (eDP and LVDS)

Type	ident	BIOS version	device-id	working
Blue AMD PCB	109-C42251-00A	M4000	682D	yes

LVDS support

• iMac10,1 21.5: LVDS version tested
• iMac9,1 24: LVDS version, tested

Memory support:

Hynix

Performance:

• GeekBench Metal and OpenCL: > 10.000
• Valley: 19.4 FPS, 811 Score
• MetalBench: 19 MRays/s
• CoreClock: 675 MHz
• Memory: 1000 MHz
• TPD: 30W

The M4000 card is of type MXM-A and will also fit into 21.5 inch models.

M5100 and W5170 (eDP and LVDS)

Type	ident	BIOS version	device-id	working
Green AMD PCB	109-C93157-00A_03	W5170M	6820	yes
Blue AMD PCB	109-C42271-01_02	M5100	6821	yes
Red Dell PCB	109-C42241-01_02	M5100	6821	yes
Blue AMD PCB	109-C42341-00C_02	M5100	6821	unknown

LVDS support

• iMac10,1 21.5: LVDS version tested
• iMac9,1 24: LVDS version, tested

Performance:

• GeekBench Metal and OpenCL: > 10.000
• Valley DELL: 23.46 FPS, 981 Score
• MetalBench: 31 MRays/s
• CoreClock: 300 MHz idle - 850 MHz max
• MemoryClock: 150 MHz idle - 1125 MHz max
• PowerDraw: 5W idle - 35W max

Memory support:

1. Elpida/Samsung, 2. Hynix BFR and 3. Hynix AFR memory. All cards listed in this section are of type MXM-A and will also fit into 21.5 inch models.

Soldering mods:

From the W5170M PCB you need to remove two resistors to let it run in most iMacs.

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Warnings:

• these cards are easy to install but complex to manage during the initial software installation.
• do not cross flash the vBIOS from the DELL card onto the other two cards, it will cause a bad flash and will make the card unusable
• a bad flash prevents the iMac from booting and running the Linux flash utility, again!
• bad flashes can only be cured by using a CH341A clip or some other nasty tricks

You need to install OpenCore in advance and add the changes posted before booting into macOS. The card will not boot into macOS without the adjusted CAIL values in the config.plist.

After installing the card it will not simply boot directly into any macOS version (WindowServer crash) unless you install and use OpenCore and apply the settings described below (I will try to get the changes added to OCLP, later).

So you need to install OpenCore onto your boot disk before booting in your current installation in normal multi user mode.

In case you have a working system before changing the card just run OLCP, select the proper MXM GPU type to AMD (GCN) and build and install OpenCore to your system and reboot. Otherwise use another Mac to create the OC settings or create a OpenCore BootCD.

The settings needed are equivalent with adding radpg=15 -wegtree apdpmod=pikera to the boot-args in the config.plist of OpenCore.

This GPU type has been used in 2015 15" MacBookPro models.

Tested systems:

• iMac12,2: sleep/wake broken
• iMac12,1: sleep/wake broken
• iMac11,1: no problems
• iMac11,3: no problems
• iMac10,1: no problems

Known issues:

• external display sync is difficult on all systems and needs the main LCD or the system to go to display sleep once after connecting the external display (press CRTL+SHIFT+EJECT to force display sleep once).

Known features:

• Airplay is working until Catalina as with any other AMD metal card on iMac11,x and iMac12,2 (without using QuickSync)
• high metal scores
• boot screen with OpenCore (GOP) or EFI (EnableGop)
• brightness control working
• GPU power management working
• needs macOS 10.8.3 or better (HD7000 support)
• still full Monterey support (no root patching needed unlike Kepler)

News:

• OCLP 0.3.2 and later support this card. So you can update OC using OCLP in future. Nevertheless the boot strap process is complex since you cannot boot the normal macOS unless OC has been installed in advance!

Credits:

• Thanks to internetzel and franetic for their dedication and time helping to get this GOP vBIOS working!